The research approach used to develop this guide is a combination of case study methodology and benchmarking of "best practices." Used
in businesses worldwide as they seek to continuously improve their operations, benchmarking has been applied more recently to education.
Benchmarking is a structured, efficient process that targets key operations and identifies promising practices, defined in comparison to traditional practice or previous practice at the selected sites and quantified, when possible, with local outcome data. The methodology used here is further explained in a background document,78 which lays out the justification for identifying promising practices based on four sources of rigor in the approach:

Theory and research base;

Expert review;

Site evidence of effectiveness; and

Systematic field research and cross-site analysis.

The steps of the research process were: defining a study scope, seeking input from experts to refine the scope and inform site selection
criteria, screening potential sites, selecting sites to study, collecting and analyzing data to write case reports, and writing a user-friendly guide.